Building roof structure

ABSTRACT

A Building Roof Structure is formed of a series of modular sections or trusses assembled to support or form a cover over a building area. Each section or truss is formed of a sheet of relatively heavy paperboard having a planar surface, with downturned opposite flanges at the edges thereof. The sections are assembled in side-by-side relation to the edges of adjacent sections and joined together by suitable fastening means. The cracks between the sections or trusses are sealed by a strip of fibrous material adhesively secured to one or more of the inturned flanges and forming a chord between opposite sides of the truss section. The planar top surfaces of the sections may also be covered with a mat of fibrous material, such as fiberglass, adhesively secured thereto which will make the roof both waterproof and add structural strength to the paperboard sections.

United States Patent Yates Apr. 2, 1974 BUILDING ROOF STRUCTURE Primar ExaminerAlfred C. Perham 1 Y t Y dl P Y [75] inventor Herbert G a at ey a Attorney, Agent, or Firm-Burns, Doane, Swecker & [73] Assignee: Panokraft Corporation of Canada Mathis Limited, Dorval, Quebec, Canada 22 Filed: July 1, 1971 ABSTRACT l A Building Roof Structure is formed of a series of [211 App! 158363 modular sections or trusses assembled to support or form a cover over a building area. Each section or [52] U.S. Cl 52/90, 52/94, 52/309, truss is formed of a sheet of relatively heavy paper- 52/579, 52/690 board having a planar surface, with downturned oppo- [51] Int. Cl. E04b 7/02, E04c 3/02 site flanges at the edges thereof. The sections are as- [58] Field of Search 52/70, 86, 90-309, sembled in side-by-side relation to the edges of adja- 52/579, 690 cent sections and joined together by suitable fastening means. The cracks between the sections or trusses are [56] References Cited sealed by a strip of fibrous material adhesively secured UNITED STATES PATENTS to one or more of the inturned flanges and forming a 3 564 785 2 1971 Kephart Jr. 52/86 x chord between Opposite Sides of the truss Section- The 3 427 767 2 1969 Schaefer.....:::::: 52 90 x Planar P Surfaces of the Sections may also be 3:l86:524 6 1965 Spaeth, Jr. 52/86 ered with a mat of fibrous material, s as fiberglass, 2,850,890 9/1958 Rubenstein 52/309 X adhesively secured thereto which will make the roof 3,271,917 9/1966 Rubenstein 52/309 both waterproof and add structural strength to the pa- FOREIGN PATENTS OR APPLICATIONS Perb"alrd Seams- 574,76l 4/1924 France 52/579 14 Claims, 11 Drawing Figures PATENTED APR 2 I974 SHEET 1 [1F 2 ATTORNEYS PATENTEU 2 97 SHEEI 2 OF 2 INVENTOR.

/ASPBfi/PT 6. 77 72-15 Y Gnu,

ATTORNEYS BUILDING ROOF STRUCTURE SUMMARY OF THE INVENTION This invention relates to improvements in Building Roof Structures as may be provided for a house or other type of building.

Paperboard material has been used for building shelter-type structures, but these were more of a collapsible nature and were not of a more permanent house structure. The roof of a building requires not only that it protect the interior of the house, but it must have sufficient structural strength to withstand the elements of nature, rain, wind, snow and the like. In the construc tion of low cost housing, the use of paperboard material for the roof or for roof trusses presents a problem in obtaining sufficient structural strength as well as protection from the elements that has been difficult of solution.

One object of this invention is to provide for the construction of a building roof or roof trusses of low cost paperboard material and yet obtain therewith sufficient structural strength for protection from the elements of nature.

Another object of the invention is to add reinforcing and protection intermediate roof sections of paperboard material so as to enable these sections to be secured together in the form of a truss, with sufficient structural strength to be used for the roof, although formed of paperboard material.

These objects may be accomplished, according to one embodiment'of the invention, by constructing a roof of a plurality of modular spans or sections, each formed of paperboard material and disposed in side-byside relation.

Each of the sections is flat or of planar form from edge-to-edge thereof, with downturned flanges on opposite edges. The respective sections are joined together by connection of these flanges of adjacent sections.

Interposed between. the opposing flanges of the sideby-side sections are strips or rovingsof fibrous material running lengthwise of the. sections and adhesively se-- cured thereto. Each. stripor roving may be formed of suitable fibrous material, such. as. fiberglass, anrl-v saturatedawithasuitable plastic adhesive, such as polyester resin, which adhesively secures the strip or roving to one orboth of the opposing faces. The strip forms a chord between. the side sections and. adds structural strength. thereto which will make the truss forming the roof sufficiently sturdy to'withstand' the elements of nature...Other structural? elements of truss design may be used? for additional:strengthening.of the roof.

Constructed. in. thisway, the. roof has aself-contained trussinco'rporated'thereimwithouti requiring aseparate framing and. separate covering. The. paperboard sectionsform. not only the: covering of the roof, but also the structure. thereof with. the added strength. supplied by the chordistripsoffibrous material.

Additional covering may be providedzover the top surface ofthe. roof. by formingsa shell: thereover as a coating on the upper surfaces of the sections. This coating preferably comprises a layer of fibrous material,

such as fiberglass, secured by an adhesive or plastic material, suchas polyester resin, that saturates the chord strips and causes the fibrous material to adhere to the surface. The coating over the roof may be rolled or molded in the form of a shell and when it hardens will form an effective covering therefor.

BRIEF DESCRIPTION OF DRAWINGS Certain embodiments of the invention are illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of a portion of a building roof illustrating this invention and with parts broken away;

FIG. 2 is a vertical section therethrough on the line 2-2 of FIG. 1;

FIG. 3 is a detail cross-section through one of the strips of strengthening material;

FIG. 4 is a detail longitudinal section through the roof substantially on the line 4-4 in FIG. 2;

FIG. 5 is a disassembled perspective view showing the joining of upright and transverse sections;

FIG. 6 is a cross-section through a portion of a roof embodying one form of this invention;

FIG. 6a is a partial top plan view thereof;

FIG. 7 is a diagrammatic view of a roof truss illustrating this invention;

FIG. 8 is a similar view showing another form thereof; and

FIGS. 9 and 10 are similar views showing still other modifications thereof.

DETAILED DESCRIPTION OF DRAWINGS The roof illustrated in FIGS. 1 to 4, as an example of this invention, is of the gable type intended to extend over a suitable building area and mounted upon upright walls or supports, generally indicated at 1 The roof extends across between the supports 1 forming a truss therebetween.

In accordance with this invention, the roof illustrated in FIGS. l to 4 comprises a plurality of sections 2 formed of flat paperboard material having planar surfaces between opposite edges thereof and substantially throughout the length thereof. Each of the sections 2 has downturned opposite edges forming flanges 3, with the flangeson one section in opposed relation to the flangeson the next adjacent sections. These flanges are secured together by suitable fastening means such, for example, as staples 4 spaced at suitable intervals along the length thereof, as indicated in FIG. 4. The flanges are of appreciable depth, 4 to 6 inches, to stiffen and add strength'to the paperboard'sections.

Extending along the edges of the flanges 3 are strips of strengthening material, generally indicated at 5 and shown more indetail in FIG; 3. This strip of strengthening material 5 preferably comprises a strand, roving or rope of fiberglass,indicatedat 5, which is saturated by a suitable adhesive applied thereover, such as'polyester resin, and'pressed firmly in place. This adhesive willbe effective for retaining the structural strength of the strand 5 and securing it rigidly to the flange of the paperboard material.

The composite of fiberglass and polyester should have at least30 percent of fibers and up to percent of polyester. This composite should be applied to a thickness of one sixty-fourth inch to one thirty-second inch, according to the strength needed.

In the form of roof shown in FIG. 1, the sections 2 are further strengthened by box girder sections, indicated generally at 8. Each of the box girder sections 8 is also formed of paperboard material having a flat bottom with upturned side flanges 9 that overlap the flanges 3 and are secured thereto by the staples 4. The box girder sections 8 extend in bridging relation between the opposite sides of the roof sections 2 that depend from the apex of the roof and thus the box girder sections have tapered end portions so as to form a horizontal area between the lower edges of the roof.

The strengthening strips 5 extend along the upper edges of the box girder sections, forming top chords, being connected together at the peak joint 5b.

Extending along the lower edge portions of the box girder sections 8 are horizontal strands 5a, forming bottom chords, which are adhesively secured to the sections and thus extend along the lower edge of the roof truss thus formed, being connected by heel joints Sc to the strengthening strands 5. There is thus provided an expanded truss effect within the roof. If desired, portions of the flanges 9 may be cut away between these strands 5 and 5a for ornamental effect, but not sufficiently to weaken the roof truss thus formed.

The aligned sections 2 on opposite sides of the ridge of the roof may be connected together in any suitable or desired way as through gussets applied to the sides of the flanges 3 or by end tabs that are connected directly together.

It is preferred also to use a covering over the upper faces of the roof sections. One form of covering that may be employed includes a mat or layer of fiberglass, indicated generally at 10, having layers of adhesive 11 which saturate the mat and adhesively secures the same to the top surfaces of the sections 2. This coating composition may be rolled or pressed firmly upon the upper surface of the sections, extending continuously over the gap between the sections and will set to form a hardened shell over the entire roof.

The interconnetion of the box side flanges 9 with the flanges 3 on the roof sections may be overlapped in any suitable or desired relation. One such arrangement is illustrated in FIG. 2, but if preferred the box flanges 9 may be disposed between the adjacent flanges 3 of the roof sections with the strand 5 between the edge portions of the flanges 9 in the manner illustrated at the bottom of FIG. 2. Either arrangement may be used as found desirable.

These sections 2 and 3 may be connected together as the sections are assembled, being secured at one edge of each section by the staples 4 and 14 before the second flange on the box section is folded to its upright position for interconnection with the flange 3. This will enable the assembly to be brought into place and secured in step-by-step relation for effective strengthening of the girder assembly by the interconnection of the flanges on the sections as well as by the strands 5 and 5a.

The strands 5 and 5a are applied to the outer faces of the flanges 3 and/or 9 as the sections are assembled throughout the length of the roof and when the material is hardened after assembly of the sections, it will form an effective tensile strength in the beam that is a part of the roof structure.

The outer ends of the roof sections 2 may be mounted in any suitable manner upon upright supports or walls. One form of support which is illustrated in FIGS. 5, 6 and 6a involves the use of upright wall sections 15, also made of paperboard material with inturned flanges 16 on opposite edges thereof. The upper ends of the flanges 16 are cut off at an angle, indicated at 17, complementary to the angle of the sloping flanges 3 on the roof sections 2 and thus be aligned with these flanges. Gussets 18 may be secured between the roof sections 2 and the side wall sections 15.

In this example, the roof sections 2 project beyond the upright wall sections 15 and the latter are provided with tongues, shown at 19, extending throughout the height of the flanges 3 of the roof sections with laterally turned tabs 20 thereon secured as by staples, adhesive or the like to the flat undersurfaces of the sections 2. This forms a secure connection between each of the roof sections 2 and the upright side wall section 15.

The outer ends of the respective channel-shaped roof sections 2 are closed by a strip 21 which may be of wood, if desired, or of other suitable material. This edge strip 21 extends continuously along the edge of the roof and will serve as a support for a gutter, or for a ladder. The paperboard material forming the flat surface of each roof section 2 may be secured to the strip 21 by nailing, indicated at 22, or in any other suitable manner.

The ends of the side flanges 3 are turned inward at 21a and secured by nails 21b to the back face of the strip 21.

The inner edge of the strip 21 is provided with a groove 23 in position to receive an edge portion of a soffet 24, the opposite edge of which has an offset flange 25 secured to the upright face of the side member 15. Thus, the soffet 24 extends between the strip 21 and the upright side wall member 15, along the outer wall closing the undersurface of the roof externally of the wall.

FIG. 6 also shows inturned tabs on the ends of the aligned roof sections 2 which are indicated at 27 and are secured together. These tabs may be sufficient or used alternately or together with gussets 28 between the aligned roof sections.

The invention is shown in FIGS. 7 to 10 applied to other forms of roofs. All of these use roof sections of paperboard material wherein the flat or planar sheets have downturned flanges at the opposite edges thereof assembled edge-to-edge, as described above. These sections may be in the form of angles or of truss pattern or of other suitable designs.

In FIG. 7, the roof sections 2 are at obtuse angles to each other and the flanges thereof are provided with strands of fibrous material, such as fiberglass, adhesively secured to the sections in the manner described above and as illustrated at 5 and 5a. In place of the box sections 8, this form of roof is provided with web sections 29 having a strand of fiberglass adhesively secured to each, as indicated at 30 in FIG. 7.

This strand 30 is secured by polyester or other suitable resin or adhesive to the edges of the adjacent webs 29 that are connected with the roof sections 2 so as to form a cross tie or bottom chord extending in bridging relation between the chords 5 of the truss of the roof sections, thus bracing the latter in the manner of a selfcontained roof truss. Each of the webs 29 may be continuous from edge-to-edge thereof or has one or more form of webs 31 or secured to the flanges on the roof sections as by staples 32 and extending continuously throughout the truss area of the roof or provided with cut-outs as desired. These webs 31 have fiberglass A jstrands 33 extending along the lower edges thereof and adhesively secured thereto forming a bottom chord on the truss. Diagonal sections or strands 34 form web members extending between the strands 33 along the lower edges of the webs 31 and the strands 5 along the flanges of the roof sections 2, thus giving a further bracing effect to the roof.

In- FIG. '9, a flat roof is indicated where the roof sections 2 extend continuously throughout the area of a flat roof from side-to-side thereof and have downi wardly extending webs 35 connected with the flanges of the roof sections. A strand 36 extends in the form of a bottom chord along the lower edges of the webs 35 with triangularly disposed strands 37 forming web members connecting the strands 5 and 36 together to give a further bracing action.

Generally, this same effect is indicated in FIG. as applied to roof sections 2 which are disposed at a slight angle to each other, and thereby form'an arch.,

fiberglassor other suitable fibrous material is saturated and adhesively secured by polyester or other suitable adhesive at the site where the building is to be" erected. Printed indications'may be applied at the fact'bry to the side faces of the inturned sections forappropriate application of the strips or rovings.

In each instance the roof is formed of a.,low cost material, such as paperboard. Combined therewith is the strip or roving of fibrous material which is applied in the pattern according to the indications, thereby forming a truss with both top and bottom chords joined to gether, with or without gintermediate? web members.

I The bottom chord is under tension due to the compression force from above. a J

In this way a trussm ay be formedfin pre-engineered form and shape. The demand on thel truss can be determined. Then, by applying the rightamount of cross tie material to the surface according to the direction of the indicia thereon, the appropriate strength will be formed to support the loads.

The word paperboard as used herein should be understood to mean board material made of paper or other relatively low-cost paper-like materials which are relatively rigid but which may vary in thickness and texture. Corrugated cardboard is an example of a suitable material for the purpose.

The use of fiberglass strands along the flanges of the roof sections, with or without additional strands extending in bridging relation therebetween, gives tensile strength to the roof sections which enables these to support substantial weight and resist wind and snow without departing from the invention as set forth in the claims.

I claim:

1. A building structure roof comprising a plurality of roof sections arranged side-by-side to form a substantially planar outer roof portion, each of the roof sections comprising a sheet of paperboard material having a planar central portion and inturned flanges on opposite side edges thereof beside the flanges of adjacent sections, means for reinforcing the roof comprising a strip of fibrous material interposed between the flanges of adjacent sections extending along said sections and molded to at least one of them in a plastic adhesive, and means securing the flanges of adjacent sections together, and a shell of material including reinforcing fibers adhesively bonded to the planar outer roof surface portion and bridging spaces between adjacent roof sections, said shell having sufficient thickness to provide an impact resistant and weatherproof roof section.

2. A building structure roof according to claim 1, wherein the flanges have a depth of at least four inches, and the strip of fibrous material extends continuously along the length of at least one of the sections.

3. A building structure roof according to claim 1,

.wherein the strip of fibrous material comprises fiber- I lass with a la er of lastic material on each side ln each instance, as descrlbed, the strip or roving of r g y p thereof.

4. A building structure roof according to claim 1, wherein the securing means comprises fastenings extending through the adjacent inturned flanges.

5. A building structure roof according to claim 4, wherein the fastenings are disposed at opposite sides of the strip.

6. A building structure roof according to claim 1, wherein the roof is in truss shape with a box girder section extending between opposite sides of the roof truss.

7. A building structure as defined in claim 1 wherein the reinforcing fibers of the shell are glass fibers and the bonding adhesive of the shell is a polyester resin.

8. A building structure as defined in claim 1 wherein the building structure roof comprises a pitched roof having a pair of substantially planar outer roof surface portions that are angularly related to each other and joined together along a substantially horizontal line forming a ridgefor the roof, and means for joining facing end edges of the roof sections along said ridge ineluding downwardly extending flanges of said paperboard sheet material. 7

9. A building structure as defined in claim 8 wherein the means for joining facing end edges of the roof sections includes gussets secured to said inturned edges of facing roof sections on opposite sides of said ridge.

10. A building structure roof comprising a plurality of roof sections arranged side-by-side to form a substantially planar outer roof surface portion, each of the roof sections including a roof truss comprising a top section including a rectangular paperboard member having downtumed opposite flanges thereon extending lengthwise of the member, a first strand of fibrous material extending along one of the downtumed flanges and adhesively secured thereto thereby forming a top chord of the truss and a second strand of fibrous material adhesively secured to one of said downturned flanges at a lower position thereby forming a bottom chord of the truss.

11. A roof truss according to claim 10, wherein the ends of the bottom chord are connected with the top chord.

12. A roof truss according to claim 10, wherein the truss has portions disposed at angles to each other with a girder wall extending therebetween, and the second strand of fibrous material extends between said angular portions and is adhesively secured to the girder wall.

13. A roof truss according to claim 12, including strands of fibrous material forming web members between the first and second strands of fibrous material and adhesively secured to the girder wall forming an expanded pattern of truss.

14. A building structure roof comprising a plurality of roof sections arranged side-by-side, each of the roof sections comprising a sheet of paperboard material having inturned flanges on opposite edges thereof beside the flanges of adjacent sections, a strip of fibrous material interposed between the flanges of adjacent sections extending along said sections and molded to at least one of them in a plastic adhesive, said roof having a truss shape with box girder sections extending between opposite sides of the roof truss, said box girder sections comprising U-shaped members having sides overlapping the flanges of the roof sections, and means securing the flanges of the adjacent sections and the sides of the U-shaped members together. 

1. A building structure roof comprising a plurality of roof sections arranged side-by-side to form a substantially planar outer roof portion, each of the roof sections comprising a sheet of paperboard material having a planar central portion and inturned flanges on opposite side edges thereof beside the flanges of adjacent sections, means for reinforcing the roof comprising a strip of fibrous material interposed between the flanges of adjacent sections extending along said sections and molded to at least one of them in a plastic adhesive, and means securing the flanges of adjacent sections together, and a shell of material including reinforcing fibers adhesively bonded to the planar outer roof surface portion and bridging spaces between adjacent roof sections, said shell having sufficient thickness to provide an impact resistant and weatherproof roof section.
 2. A building structure roof according to claim 1, wherein the flanges have a depth of at least four inches, and the strip of fibrous material extends continuously along the length of at least one of the sections.
 3. A building structure roof according to claim 1, wherein the strip of fibrous material comprises fiberglass with a layer of plastic material on each side thereof.
 4. A building structure roof according to claim 1, wherein the securing means comprises fastenings extending through the adjacent inturned flanges.
 5. A building structure roof according to claim 4, wherein the fastenings are disposed at opposite sides of the strip.
 6. A building structure roof according to claim 1, wherein the roof is in truss shape with a box girder section extending between opposite sides of the Roof truss.
 7. A building structure as defined in claim 1 wherein the reinforcing fibers of the shell are glass fibers and the bonding adhesive of the shell is a polyester resin.
 8. A building structure as defined in claim 1 wherein the building structure roof comprises a pitched roof having a pair of substantially planar outer roof surface portions that are angularly related to each other and joined together along a substantially horizontal line forming a ridge for the roof, and means for joining facing end edges of the roof sections along said ridge including downwardly extending flanges of said paperboard sheet material.
 9. A building structure as defined in claim 8 wherein the means for joining facing end edges of the roof sections includes gussets secured to said inturned edges of facing roof sections on opposite sides of said ridge.
 10. A building structure roof comprising a plurality of roof sections arranged side-by-side to form a substantially planar outer roof surface portion, each of the roof sections including a roof truss comprising a top section including a rectangular paperboard member having downturned opposite flanges thereon extending lengthwise of the member, a first strand of fibrous material extending along one of the downturned flanges and adhesively secured thereto thereby forming a top chord of the truss and a second strand of fibrous material adhesively secured to one of said downturned flanges at a lower position thereby forming a bottom chord of the truss.
 11. A roof truss according to claim 10, wherein the ends of the bottom chord are connected with the top chord.
 12. A roof truss according to claim 10, wherein the truss has portions disposed at angles to each other with a girder wall extending therebetween, and the second strand of fibrous material extends between said angular portions and is adhesively secured to the girder wall.
 13. A roof truss according to claim 12, including strands of fibrous material forming web members between the first and second strands of fibrous material and adhesively secured to the girder wall forming an expanded pattern of truss.
 14. A building structure roof comprising a plurality of roof sections arranged side-by-side, each of the roof sections comprising a sheet of paperboard material having inturned flanges on opposite edges thereof beside the flanges of adjacent sections, a strip of fibrous material interposed between the flanges of adjacent sections extending along said sections and molded to at least one of them in a plastic adhesive, said roof having a truss shape with box girder sections extending between opposite sides of the roof truss, said box girder sections comprising U-shaped members having sides overlapping the flanges of the roof sections, and means securing the flanges of the adjacent sections and the sides of the U-shaped members together. 